Identifying neurons for interoception using simultaneous profiling of activity- and projection- specific populations

项目摘要 内感是身体感觉自身内部状态的过程，对维持 通过检测使身体能够适应变化的生理变化来实现动态平衡 要求。内感功能障碍可能会导致关于这些身体的错误预测错误 需要并越来越多地被认为是许多适应不良行为和精神病的基础 精神障碍，包括成瘾和饮食障碍。尽管如此，在以下方面取得的进展甚微 识别内在知觉的潜在神经回路机制是因为非语言受试者(例如 动物模型)不能自我报告内部状态。在这里，我们提出了一种新的概念行为 在动物模型中研究内感觉以确定神经元集合的框架 对内感觉进行编码。此外，人体成像研究告诉我们，内部感觉依赖于 关键是大脑中一个研究不足的区域，即岛叶皮质，但其功能和相应的 岛叶皮质亚区(从前到后)的投射还没有得到很好的研究。 方法可以同时提供有关行为和投影的准确信息 因此需要高吞吐量的方式。分子图谱技术已经越来越多地被 对于识别可能作为基因与电路之间联系的细胞类型很有用，但目前 技术有局限性，即分析发生的方式。因此，我们还 提出了一种新的转录分子图谱技术，称为SNAP-TRAP(同时 神经元活性和投射翻译核糖体亲和力纯化)，这使得重合 活动依赖和投射特异性神经元标记物的分析。我们将对此进行验证 使用具有已知分子标记和行为的定义明确的神经电路的技术 后果。然后，我们将把这一方法应用于岛叶皮质及其在内感中的作用。 这项技术还将使我们能够将下一代RNA测序与单一核糖核酸测序进行比较。 细胞RNA测序的目的是确定用于行为验证的有用标记。最后，我们 将我们的发现映射回组织切片上，以获得空间转录信息。穿过 这些实验，我们希望获得一个全面的岛叶皮质转录图谱 可以根据特定的行为和投影精确地描绘出来，并可以用作 了解内感功能障碍如何导致适应不良行为的基础。快照- 然后，TRAP技术可以被更广泛的神经科学界用于其他大脑区域和 行为任务，以深入了解复杂行为的神经基础及其 相关的精神障碍。

Project Summary Interoception, the process by which the body senses its own internal state, is critical to maintaining homeostasis through the detection of physiological changes that enable the body to adjust to changing demands. Dysfunction in interoception may lead to erroneous prediction errors concerning these bodily needs and is increasingly considered to underlie a number of maladaptive behaviors and psychiatric disorders, including addiction and eating disorders. Despite this, little progress has been made in identifying the underlying neural circuit mechanisms of interoception because non-verbal subjects (e.g. animal models) cannot self-report internal states. Here, we propose a novel conceptual behavioral framework for studying interoception in animal models in order to identify neuronal ensembles that encode interoception. Moreover, human imaging studies have informed us that interoception relies critically on an understudied area of the brain, the insular cortex, but the functions and corresponding projections from the insular cortex subregions (anterior to posterior) have not been well-studied. Methods that can simultaneously deliver precise information concerning behavior and projections in a high-throughput way are therefore required. Molecular profiling techniques have been increasingly useful for identifying cell types that might serves as the link between genes to circuits, but current techniques have limitations, namely the modality by which the profiling occurs. We therefore also propose a new transcriptomic molecular profiling technique, called SNAP-TRAP (Simultaneous Neuronal Activity and Projection – Translating Ribosome Affinity Purification), that enables coincident profiling of both activity-dependent and projection-specific neuronal markers. We will validate this technique using a well-defined neural circuit with known molecular markers and behavioral consequences. We will then apply the methodology to the insular cortex and its role in interoception. This technique will also enable us to make comparisons of next-generation RNA-sequencing to single- cell RNA sequencing for the purpose of identifying useful markers for behavioral validation. Lastly, we will map our findings back onto tissue sections to achieve spatial transcriptomic information. Through these experiments we hope to achieve a comprehensive transcriptomic map of the insular cortex that can be precisely delineated according to particular behaviors and projections, and can be used as a basis for understanding how dysfunction in interoception leads to maladaptive behaviors. The SNAP- TRAP technique may then be used by the broader neuroscience community in other brain regions and behavioral tasks to gain insights into the neural underpinnings of complex behaviors and their associated psychiatric disorders.